Arc Flash PPE

[WDeanN]

It is my understanding that once an arc flash analysis had been performed the PPE categories in NFPA70E can be ingnored, and PPE should be selected based on the energy level.

Given this, when should face shields, balaclavas, AF hoods be worn? Do you limit their use to a particular energy level as the NFPA 70E tables do? Do you wear them all of the time? I would be interested to know what other facilities are doing about this.

 

[jim dungar]

It is my understanding that once an arc flash analysis had been performed the PPE categories in NFPA70E can be ingnored, and PPE should be selected based on the energy level.

Given this, when should face shields, balaclavas, AF hoods be worn? Do you limit their use to a particular energy level as the NFPA 70E tables do? Do you wear them all of the time? I would be interested to know what other facilities are doing about this.

NFPA 70E requires you to determine the incident energy level (there are several methods, the calulations in IEE1584 are only one method). After you have determined the AFIE you need to wear enough PPE to meet that level. The PPE manufacturer will tell you if hoods and face shields are required.

But, NFPA 70E also allows you the option of using their "task tables" if calculations are not performed. After the hazard category is determined then the correct PPE is chosen from a second table. There is also a third table that provides a minimum cal/cm^2 rating for each hazard category. This table is often "read backwards" with the result of assigning hazard categories based to energy levels (i.e. a calculated energy of 3 cal/cm^2 requires hazard category 1 PPE).

 

[WDeanN]

Jim,
I really don't like the idea of being captive to the PPE manufacturer. The real point is, do you require AF face shields for a 3 calorie hazard? Most of these are rated for 8 cal/cm2. Do you only require them for a 4-8 calorie hazard? Should a balaclava be required anytime a face shield is worn, or should that be based on an assessment of the arc flash boundary and if the arc flash is likely to wrap around the face shield?

 

[davidr43229]

WDeanN,
A cleverly worded question:

Typical Protective Clothing Systems
Hazard/Risk Category Clothing Description (Typical number of clothing layers is given in parentheses) Required Minimum Arc Rating of PPE [(J/cm2(cal/cm2)]

0 Non-melting, flammable materials (i.e., untreated cotton, wool, rayon, or silk, or blends of these materials) with a fabric weight at least 4.5 oz/yd2 (1) N/A
1 FR Shirt and FR pants or FR coverall (1) (2-4) Cals
2 Cotton underwear - conventional short sleeve and brief/shorts, plus FR shirt and FR pants (1 or 2) (4-8) Cals
3 Cotton underwear plus FR shirt and FR pants plus FR coverall, or cotton underwear plus two FR coveralls (2 or 3) (8-25) Cals
4 Cotton underwear plus FR shirt and FR pants plus multi-layer flash suit (3, or more) (25-40) Cals

I know you wanted "Facility-People" to answer this, however at 3 Cals, it represents a Level 1, which Safety Galsses/ Goggles are required. At Level 2 (4-8 Cals & above you eneter into the Faceshield/Hood area.

 

[jim dungar]

NFPA 70E 130.3(A) says to perform a hazard study to deletermine the incident energy.

130.3(B) says to provide FR clothing and other PPE per the results of the study OR to select PPE based on the task tables of 130.7(C)(9)(a).

130.7(C)(3) says PPE for head, neck, and face must be provided when it is needed.

130.7(C)(10) says to chose PPE from table 130.(C)(10) if you have used the task tables.

Table 130.7(C)(11) gives equivalent arc ratings to the hazard categories of 130.(C)(10). A FPN to 130.7(C)(11) says to contact the clothing manufacturer to meet arc ratings.

Table 130.7(C)(11) is often used backwards to chose hazard category PPE combinations based on maximum incident energies.

Personally, I follow my company's ESWP program which uses the PPE combinations of 130.7(C)11 based on maximum levels of incident energy.

 

[WDeanN]

Jim,

130.3(B) says to provide FR clothing and other PPE per the results of the study OR to select PPE based on the task tables of 130.7(C)(9)(a).

130.7(C)(3) says PPE for head, neck, and face must be provided when it is needed.

I am performing the study. So, how do you determine when PPE for head, neck, and face is needed? A blanket policy usually results in over dressing. Besides, it's next to impossible to see through some of those face shields. God forbid you had to lift a green ground wire, or work with a multi-conductor cable.

Also:

Table 130.7(C)(11) is often used backwards to chose hazard category PPE combinations based on maximum incident energies.

This usually results in being over dressed for the hazard, and can make it more hazardous to work. Being an electrician and the person performing the analysis and recommending policies, I want to find the best balance between protection and comfort. Being too conservative results in people being unable to work, or unwilling. (Like someone from another thread.) Being too liberal results in injury or death.

 

[jim dungar]

This usually results in being over dressed for the hazard, and can make it more hazardous to work. Being an electrician and the person performing the analysis and recommending policies, I want to find the best balance between protection and comfort. Being too conservative results in people being unable to work, or unwilling. (Like someone from another thread.) Being too liberal results in injury or death.

choice 1:
You have an incident energy value. Contact a clothing manufacturer and find out what clothing is avialable for the value.

choice 2:
Do like many other locations. Take your incident energy value and read backwards in table 110.7(C)(11), for example, 3 cal/cm^2 is equal to a hazard category 1. Look up hazard category 1 requirements in table 110.7(C)(10) and find that the only face protection is "safety glasses". Note how the actual task tables are not used.

choice 3:
Make up your own requirements.

 

[kingpb]

Word of caution:

Arc flash analysis is NOT a one time event. IMO this has been one of the biggest misunderstandings regarding arc flash. The plant needs to be modeled, the model needs to be updated every time a change is made to the system. Changes to the system not only include addition/subtraction of equipment, but also switching that would cause a different interconnection of busses. Also, the amount of fault current available from the utility should be verified periodically, as this could have an impact on protective device settings, resulting in longer tripping times and therefore higher energy release during an event.

Many people out there are looking for the cheapest way to meet NFPA 70E, in doing so they are hiring someone to run a onetime arc flash analysis, putting on stickers and thinking all is good. This situation provides a false sense of security for those involved. IMHO, anyone that does not offer, as part of there service to help set-up the facility with the tools and training they need to keep the arc flash analysis current, does not have the first clue as to what they are doing, and should be avoided.

Arc flash analysis, in order to comply with the hot working requirements of NFPA 70E is not a cheap proposition, beware of cheap prices from consultants.